Cab signal system.



D. J. McGARTHY. GAB SIGNAL SYSTEM.

APPLIOATIOK IILED [A119, 1908.

Patented Oct. 13,1908.

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Patented Oct. 13, 1908.

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EPMJIQ, M (M11154 1). J. McGARTHY.

GAB SIGNAL SYSTEM.

APPLICATION FILED HAY 19, 1908.

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UNITED STATES PATENT OFFICE.

DANIEL J. MCCARTHY, OF WILKI NSBURG, PENNSYLVANIA, ASSIGNOR TO THE UNIONSWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPORATION OFPENNSYL- I VANIA. I

CAB SIGNAL SYSTEM.

Specification of Letters Patent. Patented Oct. 13, 1908.

Application filed Kay 19, 1008. Serial No. 483,645.

To all whomdtmay concern:

Be it known that I, DANIEL J. MCCARTHY, of VVilkinsburg, Alleghenycounty, Pennsylvania, have invented a new and. useful Cab Signal System,of which the following is a full, clear, and exact description,reference being had to the accompanying drawings, forming part of thisspecification, in

which Figure- 1 is a diagram illustrating one form of my invention; Fig.2 is a similar view but with one of the trains or vehicles in adifferent position; and Fig. 3 is adiagram showing a modification. a

My invention relates to a. system of railway signaling in which thesignals are placed upon the train and commonly known in the 1 islocated. That isto say, it will indicate skilled in the art withoutdeparting from the spirit and scope of the invention as defined in theappended claims.

deferring first to Figs. 1 and 2, the letters A, B, C and 'D designatesuccessive block sectlons'of a railway track. R, R designate the trackrails of the block section B, and

R R designate the. track rails of the block section C. Sis a semaphoreor other track signal which guards the entrance to the block A; S is thesignal which guards the entrance to the block B, and S is the signalwhich uards the entrance to the block C. These signals may be operatedby any of the well known systems.

1 and 2 are signal mains in which flows an alternating current suppliedby a generator G. The frequency of this current can be of any value whenthe propulsion power for the cars or trainsis other than an alternat-ingcurrent, When the propulsion power is alternating current, the frequencyof the generator G is preferably of a value which is ifferent from thatof the ropulsion current.

T is a transformer block B, and T is a transformer for su plying theblock C. Each of these trans ormers has one primaryand two secondarycoils or windings. The secondary coils of the transformerT are desi ated14 and 15 and the secondary coils o the transformer T are designated 16and 17. The primary coil of each transformer is connected across thesignal mains 1 and 2. The secondary coil 14 of the transformer T isconnected by one terminal to the middle point of the impedance coils 3through a circuit breaker 4: which is cont-rolled by the movement of thesignal S. The other terminal of the coil or or supplying the I wmding 14is connected to the middle point of the. impedance coils 5 at theopposite ends of the block B by a conductor 7. The impedance coils 3 andfimay be the well known induction bonds which are used in blockSignaling 11 el roads and which form a path for the propulsion currentfrom one block section to another, but which serve to hold back thealternating signal current. The secondary coil 16 of the transformer Tis in like manner connected by one terminal with the inductance bond 5through a circuit breaker 6 controlled by the signal S and by its otherterminal with the middle point of the bond at the opposite end of theblock section C. The other secondary COllS 15 and 17 are respectivelyconnected across the track rails R, R and R R of the blocks B and C.

10 is a conventionalrepresentation of a train, car or vehicle which inFig. 1 is shown within the block section B, and 24.- is a similarrepresentation of another train, car or vehicle which in Fig; 1 is shownas occupying the block section C. Each car, locomotive or other vehiclehas thereon an inductor v whlch is shown as consistlng of two 00118 orwindings which are laced in inductive rela- 3 vehicle 10 and thecorresponding signal is v indicated at 11. The similar coils or windingson the-car or vehicle 24 are designated as 19 or '20 and thecorresponding cab slgnal is indicated at 21. Each car or vehicle alsocarries another inductor which is shown as 7 consisting of two coils ininductive relation to the track rails and including a signal orindicating device in either circuit. These two coils on the car orvehicle 10 are indicated by the numerals 12 and 13 and the correspondingsignal is indicated at 18.

The corresponding coils or windings on the car or vehicle 24 aredesignated as 22 and 23 and the cab signal operated thereby is indicatedat 25. These cab signals may be either visual or audible signals, orboth, and their operative mechanism is electro-responsive to the currentgenerated in their circuits by the inductors.

The secondary coil 14 or 16 causes a current to flow through the trackrails of the corresponding block and through the wire or conductor 7when the signal S or S' is in clear position so that the correspondingsignal-controlled circuit breaker 4 or 6 is in closed position. Thecoils of those inductors which operate the cab signals 11 and 21 are soconnected that the current induced in them by currents from thesesecondary coils 14 and 16 will flow through the inductors 11 and 21 andwill cause them to indicate a condition corresponding to the position ofthe signals S, S. Thus in Fig. 1, the signal S is in its clear positionand a current is therefore flowing in the track rails from the secondarywinding 14. The current induced in the coils 8 and 9 will thereforecause the cab signal 11 to indicate a clear position as shown. Thesignal S, however, is at danger position and therefore no current isflowing into the rails R'-, R from the secondary wet the transformer T.The cab signal 21 indicates a corresponding danger position. I

The signals indicated at 18 and 25 are operated by a current flowing inthe track rails from the secondaries 15 and 17. In the 7 position of thetrain or vehicle 10 as shown tive 10 and the signal S the indicator 18will indicate a clear position. In the same way the indicator 25 willshow a clear condition of the track so long as there is no train orother vehicle between the train or vehicle 24 and the signal S. Suppose,however, that the train or vehicle 24'has moved into the block B beyondthe danger signal S as shown in Fi 2. The signal S being clear, currentwill e flowing along the rails R, R and as there is no difference ofpotential between the rails for this current the locomothem through theaxles of the locomotive 10 so that the signal 25 will indicate thatthere is another car or train in advance in the same block.

In block signaling systems, the signals are usually so constructed andarranged that any derangement of the controlling circuits will causethe'signals to indicate danger. 'To prevent delays of trafiic from suchcauses. it is customary for the train that has been stopped by a dangersignal to wait acertain length of time and if the signal does not changewithin this time, to proceed under caution to the next si a1. By thesystem here described, the indlcators 18 and 25 will in allsuch casesindicate the presence of any other train or vehicle in advance in thesame block. I Supposing'the signal S to have failed in the dangerposition and the locomotive or other vehicle 10 to have" passed out ofthe blocks A and'B so that the signal S is at clear position. thelocomotive-24 in passing intothe block B will have" its indicators 25and 21 show clear, thereby indicatingthat no other train or car is inthat block and that the signal S is clear. Therefore the locomo-- tive24 need not proceed under caution. thus saving time and also giving apositive indication that the signal S is out of order.

Fig. 3 shows another form of the invention in which the inductors 26 and27 which operate the cab signals or indicators 18 and 2:") are placedparallel with and in such relation to the axles of the locomotive thatwhen an alternating current flows through the axles, an electro-mot-iveforce will be induced in these conductors, thereby causing a current toflow through the indicators 18 and 25. The line wire 2 is connected tothe rails R, R of the blocks B and C through the cir cuitbreakers 28 and29 controlledv by the track signals S, S. The line wire 1 is connecteddirectly to rails R, R- at opposite ends of the blocks B and C. Signal Sbeing in the clear position, a current is flowing from the line Wire 2*through the rail R, through the axles of the locomotive orothervehicle10 and through rail R back to the linewire 1", As stated above thiscauses a current to flow through the indicator 18 'which will indicate aclear positlon corresponding to the signal S. The signal being in thedanger position and circuit breaker29 bein open no current will beflowing through rails R R fromthe line wires 1 and 2 so that theindicator on the locomotive or othervehicle 24 willnot utilized tooperate t 1e cab signals indicatin the condition of the track and of thetrac signals in the mannerdescribed. 1

1. In a cab signaling system, sectional track rails, track signals,means for sueppllying current to the track rails control'l the movementof the track signals, an in- "dnctor carried by the vehicle and arrangedto have a circuit'inducedtherein by current flowing in the track circuitand a signal de} vice on the vehicle which is responsive to current'generated by the inductor; substantially as described.

'2. In a cab signaling system, sectional track rails, track signals,means for sup lying current to the track rails controlle bythemovement'- of the track signals, an indnctor carriedby-the vehicle andarranged the movement of thetrack si in inductive relation to an axle"thereof, and a signal device. on the vehicle responsive to currentgenerated by the inductor; substantially, as described.

In a cab signalin system, an indicator in the cab or other-vehicle forindicating the condition of -an advance track signal, a secthe track ofthat blockirrespective of the position of the track si als, trackcircuits.

and means carried by t e vehicle'and operated from the track circuitsforoperatinv.

said indicators; substantially'as describe "4. In a cab signalingsystem, sectional track rails, track signals, means for sup 'ly-' ingcurrent to the track rails controllefby v als,-an indicator on the'cabor other vehicle arranged to'be operated by the current controlled bythe movement of thetrack signals, asecond indicator on-the cab or othervehicle and a second track circuit for o crating the-last namedindicator; 'substantlally asdescribed. 5.111 a cab signaling system,sectional track rails, transformers for su plying currents to thetrack.rails, each 0 said trans-v formers having two secondary coils "orwindconnected to the track rails, track si i m n'aIi, circuit breakerscontrolled by thetrac signals for controlling the supply of currentvstantia y as-described. cud-indicator for indicating the condition of;

from one of the transformer secondaries, in

dicatin means-on thecab or other vehicle and in uctors carried by'thejehicle and arranged to have current induced in them v, by currentsflowing in the track-circuits for operating the indicator; substantiallyas described. r i 6. Inv a cab signaling system, sectional track rails,transformers for supplying cu'rsaid trans rents to 't-hetrack rails,each 0 formers having two secondary 'windin r cons nected to the trackrails, track signa is, cir j cuit breakers con-trolled'by the track'sl=for controlling'the supply. from one o the als transformer secondariesto the track rails,

two different indicators carried by the cab or other vehicle, and aninductor for operat-= ing each of said indicators, each of said ln -iductors arranged to-have a current induced therein by the currentflowing from one of the transformer secondaries; substantially asdescribed.

7 In a cab signaling system, the combina I I tion withsectional trackrails and inductive.

bonds connecting'the different blocksor sec- I I tions, of transformershaving secondary coils whose opposite terminals are connected to theinductive bonds at opposite ends of 1 the corresponding blocks or.sections, cab signals or indicators and inductors carried by the cab orother vehicle "and arranged to be operated by the current suppliedb 1said secondaries, together withtrack signa s and circuit breakersoperated thereb 'for controllin the circuits of said secon arie's; sub--6 8; In a 'cab. signaling system, the combina:

tion with sectional track rails, of transformem for supplying current tosaid rails, each of said transformers having two' secondary 'coilsorwindings, one of the secondary coils or windings of each transformerbeingco'nhected' directly across the track rails,; and thev other'oisaid coils or windings of each transformer being connected by itsopposite. terminals with both track'rails at opposite ends of thecorresponding block or section,

together with si aling or indicating mechanlsm on the ca s or othervehicles responsive respectively to currents flowing in-said rails fromthetwo coils or windin of the transformer; substantiall as descri d. Intestimony whereof, my hand.

- DANIEL ,J'. McCARTHY..

Witnesses:

' A, L- VENQILL',

. R. L..KISTLE R.

have'hereunto set

